Most photons of an organic light emitting diode (OLED) device limited between an organic light emitting layer and a glass substrate are induced due to gradients of index of refractions among an organic material, a substrate, and air, such that only from 20% to 30% of the photons can be emitted out of the device.
In order to improve a light extracting efficiency of a bottom of the OLED, a layer of a high index of refraction substrate is further introduced to transfer the photons outside the substrate. Nanometer/micrometer metal oxide particles with a high index of refraction, such as TiO2, ZrO2, and so on, are added as a scattering medium to change a direction of light propagation for emitting much more photons out of the device. However, a drawback of this method is that the index of refraction of the scattering medium is relatively high, and the difference between the substrate and the scattering particles is reduced. The scattering effect in the substrate is greatly reduced, and the light extracting efficiency is reduced.
As a result, it is necessary to provide an organic light emitting diode device and a display apparatus to solve the problems existing in the conventional technologies.